DESCRIPTION (provided by investigator): Prematurely associated respiratory failure is a growing public health problem. Although mortality has dropped with advances in perinatal care, this condition consumes considerable healthcare resources and is increasingly associated with worrisome long-term morbidity, developmental delay, and family burden. Inhaled nitric oxide (iNO), a selective pulmonary vasodilator that improves short-term outcomes in term neonates with respiratory failure, may benefit premature infants. Consequently, a new NHLBI-funded randomized controlled trial (NHLBI iNO RCT) will assess the effect of iNO on the combined end-point of mortality or oxygen dependency at 36 weeks post conceptional age in 800 infants with prematurely associated respiratory failure. However, prematurity-associated respiratory failure has a different etiology from respiratory failure in term infants and the wide array of long-term consequences that may be affected by iNO are not captured under the existing study design. We therefore propose to extend and enhance the follow-up of the NHLBI iNO RCT. Specifically, we aim to assess the effects of iNO use on: #1. - long-term clinical and childhood developmental outcomes; #2. - family burden; and #3. - healthcare costs of prematurity-associated respiratory failure. Under aim #4, we will use data from aims #1-3 to assess the cost-effectiveness of iNO in ventilated premature infants. We will achieve these aims by augmenting the NHLBI iNO RCT data collection with: i.) survival follow-up for an average of 4 3/4 years; ii.) comprehensive, standardized follow-up clinic visits at 1,2, 3, and 4 1/2 years to assess clinical outcomes, childhood development, and family burden; iii.) structured telephone interviews with parents every 3 months in year 1 and every 6 months thereafter for an average of 4 1/2 years to assess chronic morbidity and post-discharge healthcare use; iv.) collection of detailed hospital bills for the primary hospitalization, and; v.) a comprehensive analysis plan. This study will allow us to determine the long-term consequences of iNO therapy in this condition, aiding clinicians, families, and policymakers and immediately affecting care of critically ill infants. By combining with the NHLBI iNO RCT, we take advantage of an important opportunity to gather prospective long-term outcome data in a randomized fashion. Our proposal will significantly increase the return on investment in the RCT through a greater understanding of the impact of iNO therapy from a societal perspective. Neonatal intensive care has changed dramatically in the last ten years. This study will also provide contemporary information on the long-term outcomes of prematurity-associated respiratory failure following modern management. Finally, our data will allow assessment of the robustness of early proxies for subsequent outcomes, key for future study design in this area.